For his medical-device startup, John Dinusson applies the basic principle of evolution: adaptability.

His Minneapolis-based company, OrthoCor Medical Inc., has found creative ways to launch its signature product and raise funds amid a tough environment for med-tech startups.

In 2006, OrthoCor paid the University of Minnesota to help develop a device that targets knee pain, Active Knee System. Patients wrap the system around an aching knee, typically wearing it during two-hour therapy sessions. Pods attached to the device activate electromagnetic waves and heat to reduce swelling and inflammation associated with pain.

Dinusson said the device is the first product to combine two established methods of alleviating pain: pulsed electromagnetic field technology (PEMF) and heat.

William Durfee, a professor of design education at the university’s department of mechanical engineering, was a faculty adviser to the graduate course of business and engineering students who helped design and market Active Knee System. He said the idea behind the device was well-defined, but OrthoCor was uncertain what direction to take it. The student team interviewed potential users to identify a need for the product.

They discovered an enormous market populated by baby boomers suffering joint pain. Also at the time, the American Academy of Orthopedic Surgeons said arthritis was a common chronic condition, with 12 million patients visiting physicians for knee pain that year.

Kin Jo-Sham, a University of Minnesota doctorate student in electrical engineering, led the team designing the device. He later became OrthoCor’s chief operating officer.

A former venture capitalist, Dinusson took advantage of Minnesota’s angel investment tax credit to raise money for his startup. He pulled in $2.5 million in capital through June of last year, a time when investors were skittish.

In 2011, OrthoCor sold 2,000 devices with the help of gorilla marketing. The firm pitched products to media outlets, while establishing an online presence.

A March 2011 WCCO feature of the device captured the attention of “The Dr. Oz Show,” which showcased Active Knee System to 3 million viewers in November. Traffic to OrthoCor’s website subsequently skyrocketed to 20,000 unique page views per day from an average of about 20, Dinusson said.

On the show, Dr. William Pawluk advocated for the benefits of PEMF technology to alleviate pain. Pawluk calls himself a “personal testimonial to the fact that OrthoCor gets the job done.” He used Active Knee System therapy to treat his own chronic knee pain. He now recommends the device to patients in his Maryland integrative-medicine practice.

Active Knee System is an important alternative to medication for those who suffer chronic or acute knee pain, particularly arthritis, Pawluk said.

“It doesn’t numb you or dumb you. This does the job as well or better without any toxicity whatsoever,” he said. “This is a tremendously important alternative to what’s available.”

A former assistant professor at John Hopkins University, Pawluk isn’t compensated by OrthoCor, but he has been a paid advocate for PEMF treatments.

OrthoCor is now closing another $3 million fundraising round. Late last year, Medicare assigned the company’s device a reimbursement code. It’s planning to market and distribute its products nationally, with hopes to crack the European market by 2013, Dinusson said.

“We’re an exciting new technology with a huge patient population,” he said.

Dinusson projects sales will increase fivefold this year. (He doesn’t disclose annual sales.) The disposable pods cost $195 for a set of 15 therapies while the main fabric device costs $495. Patients can wear it resting or during activity.